scholarly journals Liquid-Liquid Flow Pattern Prediction Using Relevant Dimensionless Parameter Groups

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4355
Author(s):  
Olusegun Samson Osundare ◽  
Gioia Falcone ◽  
Liyun Lao ◽  
Alexander Elliott
Keyword(s):  
Froude Number ◽  
Flow Pattern ◽  
Liquid Flow ◽  
Dimensionless Parameter ◽  
Experimental Studies ◽  
Flow Patterns ◽  
Viscous Force ◽  
Water Fraction ◽  
Flow Pattern Map ◽  
Eotvos Number

Accurate predictions of flow patterns in liquid-liquid flow are critical to the successful design and operation of industrial and geo-energy systems where two liquids are jointly transported. Unfortunately, there is no unified flow pattern map, because all published maps are based on limited ranges of dimensional parameters. Dimensional analysis was performed on oil-water horizontal flows, to obtain some relevant dimensionless parameter groups (DPG) for constructing flow pattern maps (FPM). The following combinations of DPG were used: (i) the ratio of mixture Reynolds number to Eötvös number versus water fraction, (ii) the ratio of Weber number to Eötvös number versus water fraction, (iii) the mixture Froude number versus water fraction, (iv) the water Froude number versus oil Froude number, (v) the ratio of gravity force to viscous force versus water fraction. From twelve published experimental studies, 2696 data points were gathered and analysed covering a variety of flow patterns including stratified, stratified mixed, dispersed oil in water, dispersed water in oil, annular and slug flows. Based on the performed analysis, it was found that flow patterns could occupy more than one isolated region on the DPG-based flow pattern map. None of the combinations of DPG can mark out all the considered flow patterns, however, some combinations of DPG are particularly suitable for marking out the regions associated with some flow patterns.

Liquid-Liquid Flow Patterns in Microchannels

2017 ◽  
Author(s):  
Zhen Cao ◽  
Zan Wu ◽  
Mehdi Sattari Najafabadi ◽  
Bengt Sunden
Keyword(s):  
Aspect Ratio ◽  
Flow Pattern ◽  
Liquid Flow ◽  
Flow Patterns ◽  
Continuous Phase ◽  
Hydraulic Diameter ◽  
Intermittent Flow ◽  
Dimensionless Number ◽  
Dispersed Phase ◽  
Flow Pattern Map

In the present work, liquid-liquid flow patterns positioned 40 mm downstream the inlet of microchannels were experimentally investigated, including the effect of hydraulic diameter (Dh), liquid properties, aspect ratio of cross section (a) and inlet configuration. Deionized water, butanol, toluene and hexane were selected as probe fluids with water as the continuous phase. Cross-inlet microchannels of 200 μm * 200 μm (Dh = 200 μm), 400 μm * 400 μm (Dh = 400 μm), 600 μm * 600 μm (Dh = 600 μm) and 600 μm * 300 μm (Dh = 400 μm) as well as a T-inlet microchannel of 600 μm * 300 μm (Dh = 400 μm) were tested. For the tests in the microchannels of Dh = 600 μm and 400 μm, the superficial velocities of the dispersed phase and continuous phase varied between 0.3 mm/s and 12 mm/s and between 0.2 mm/s and 50 mm/s, while in the microchannel of Dh = 200 μm the superficial velocities of the dispersed phase and continuous phase ranged from 0.3 mm/s to 21 mm/s and from 0.2 mm/s to 150 mm/s. Annular flow, deformed interface flow, slug flow, intermittent flow, droplet and slug train flow and droplet flow were detected in the experiment. It shows that flow patterns depend on the hydraulic diameter, liquid properties, inlet configuration and aspect ratio significantly. Dimensionless analysis was employed to develop universal flow pattern maps regardless of the hydraulic diameter and liquid properties. It is indicated that an acceptable universal flow pattern map was derived based on the redefined dimensionless number Rei0.2 *Wei0.4, especially for the boundaries of the slug-droplet transitions, which are independent on the hydraulic diameter to some extent. The other dimensionless number Wei*Ohi worked rather effectively to develop a universal flow pattern map independent on liquid properties. The boundaries of the flow pattern transitions in different liquid-liquid flow almost overlap with each other.

Energy of Intrinsic Mode Function for Gas-Liquid Flow Pattern Identification

2012 ◽  
Vol 19 (4) ◽  
pp. 759-766 ◽  
Author(s):  
Zhiqiang Sun ◽  
Hui Gong
Keyword(s):  
Flow Pattern ◽  
Liquid Flow ◽  
Average Energy ◽  
Flow Patterns ◽  
Pattern Identification ◽  
Intrinsic Mode Function ◽  
Flow Pattern Map ◽  
Mode Function ◽  
Gas Liquid Flow ◽  
Flow Pattern Identification

Abstract Gas-liquid flows abound in a great variety of industrial processes. Correct recognition of the regimes of a gasliquid flow is one of the most formidable challenges in multiphase flow measurement. Here we put forward a novel approach to the classification of gas-liquid flow patterns. In this method a flow-pattern map is constructed based on the average energy of intrinsic mode function and the volumetric void fraction of gas-liquid mixture. The intrinsic mode function is extracted from the pressure fluctuation across a bluff body using the empirical mode decomposition technique. Experiments adopting air and water as the working fluids are conducted in the bubble, plug, slug, and annular flow patterns at ambient temperature and atmospheric pressure. Verification tests indicate that the identification rate of the flow-pattern map developed exceeds 90%. This approach is appropriate for the gas-liquid flow pattern identification in practical applications.

scholarly journals Flow Pattern Map of Flow Boiling in a Rectangular Channel Filled with Porous Media

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2440
Author(s):  
Youngwoo Kim ◽  
Dae Yeon Kim ◽  
Kyung Chun Kim
Keyword(s):  
Porous Media ◽  
Flow Pattern ◽  
Flow Regime ◽  
Annular Flow ◽  
Flow Boiling ◽  
Rectangular Channel ◽  
Flow Patterns ◽  
Flow Pattern Map ◽  
Mist Flow ◽  
Churn Flow

A flow visualization study was carried out for flow boiling in a rectangular channel filled with and without metallic random porous media. Four main flow patterns are observed as intermittent slug-churn flow, churn-annular flow, annular-mist flow, and mist flow regimes. These flow patterns are clearly classified based on the high-speed images of the channel flow. The results of the flow pattern map according to the mass flow rate were presented using saturation temperatures and the materials of porous media as variables. As the saturation temperatures increased, the annular-mist flow regime occupied a larger area than the lower saturation temperatures condition. Therefore, the churn flow regime is narrower, and the slug flow more quickly turns to annular flow with the increasing vapor quality. The pattern map is not significantly affected by the materials of porous media.

Experimental Study on Flow Patterns of Decaying Swirling Gas-Liquid Flow in a Horizontal Pipe

2020 ◽  
Author(s):  
Shuai Liu ◽  
Li Liu ◽  
Jiarong Zhang ◽  
Hanyang Gu
Keyword(s):  
Flow Pattern ◽  
Liquid Flow ◽  
Separation Efficiency ◽  
Swirling Flow ◽  
Flow Patterns ◽  
Two Phase ◽  
Horizontal Pipe ◽  
Gas Removal ◽  
Swirl Vane ◽  
Gas Liquid Flow

Abstract Swirling flow is one of the well-recognized techniques to control the working process. This special flow is widely adopted in swirl vane separators in nuclear steam generator (SG) for water droplet separation and the fission gas removal system in Thorium Molten Salt Reactor (TMSR) for gas bubble separation. Since the parameters such as separation efficiency, pressure drop and mass and heat transfer rate are strongly dependent on the flow pattern, the accurate prediction of flow patterns and their transitions is extremely important for the proper design, operation and optimization of swirling two-phase flow systems. In this paper, using air and water as working fluids, a visualization experiment is carried out to study the gas-liquid flow in a horizontal pipe containing a swirler with four helical vanes. The test pipe is 5 m in length and 30 mm in diameter. Firstly, five typical flow patterns of swirling gas-liquid flow at the outlet of the swirler are classified and defined, these being spiral chain, swirling gas column, swirling intermittent, swirling annular and swirling ribbon flow. Being affected by the different gas and liquid flow rate of non-swirling flow, it is found that the same non-swirling flow can change into different swirling flow patterns. After that, the evolution of various swirling flow patterns along the streamwise direction is analyzed considering the influence of swirl attenuation. The results indicate that the same swirling flow pattern can transform into a variety of swirling flow patterns and subsequent non-swirling flow patterns. Finally, the flow pattern maps at different positions downstream of the swirler are presented.

scholarly journals Gas–liquid Flow Pattern Recognition Based on Wavelet Packet Energy Entropy of Vortex-induced Pressure Fluctuation

2013 ◽  
Vol 13 (2) ◽  
pp. 83-88 ◽  
Author(s):  
Zhiqiang Sun ◽  
Shuai Shao ◽  
Hui Gong
Keyword(s):  
Pattern Recognition ◽  
Flow Pattern ◽  
Liquid Flow ◽  
Pressure Fluctuation ◽  
Bluff Body ◽  
Flow Direction ◽  
Wavelet Packet ◽  
Flow Patterns ◽  
Energy Entropy ◽  
Gas Liquid Flow

Here we report a novel flow-pattern map to distinguish the gas-liquid flow patterns in horizontal pipes at ambient temperature and atmospheric pressure. The map is constructed using the coordinate system of wavelet packet energy entropy versus total mass flow rate. The wavelet packet energy entropy is obtained from the coefficients of vortex-induced pressure fluctuation decomposed by the wavelet packet transform. A triangular bluff body perpendicular to the flow direction is employed to generate the pressure fluctuation. Experimental tests confirm the suitability of the wavelet packet energy entropy as an ideal indicator of the gas-liquid flow patterns. The overall identification rate of the map is 92.86%, which can satisfy most engineering applications. This method provides a simple, practical, and robust solution to the problem of gas-liquid flow pattern recognition.

Surfactant Use for Slug Flow Pattern Suppression in a Horizontal Pipe

2003 ◽  
Author(s):  
R. J. Wilkens ◽  
S. R. Glassmeyer ◽  
G. J. Rosebrock ◽  
K. M. Storage ◽  
T. M. Storage
Keyword(s):  
Flow Pattern ◽  
Liquid Flow ◽  
Pipe Flow ◽  
Slug Flow ◽  
Flow Patterns ◽  
Flow Transition ◽  
Horizontal Pipe ◽  
Surfactant Additive ◽  
Gas Liquid Flow

A set of experiments was performed to study flow pattern suppression in gas-liquid pipe flow by means of surfactant additive. Results suggest that addition of the surfactant to gas-liquid flow significantly reduces the occurrence of slug flow. In addition, previously unreported flow patterns were observed to exist between slug and dispersed bubble flows. It is concluded that new mechanisms for slug flow transition need to be considered.

Flow Pattern Prediction in Electrical Submersible Pump (ESP) Under Gassy Flow Conditions Using Transient Multiphase CFD Methods With Visualization Experimental Validation

2018 ◽  
Author(s):  
Jianjun Zhu ◽  
Ruben Cuamatzi-Melendez ◽  
Jose Alberto Martinez Farfan ◽  
Haiwen Zhu ◽  
Jiecheng Zhang ◽  
...  
Keyword(s):  
Flow Pattern ◽  
Liquid Flow ◽  
Flow Patterns ◽  
Numerical Results ◽  
Submersible Pump ◽  
Eulerian Model ◽  
Cfd Simulations ◽  
Flow Rates ◽  
Electrical Submersible Pump ◽  
Multiphase Cfd

This paper presents a numerical study of flow pattern recognition inside the rotating impeller of electrical submersible pump (ESP) using the transient multiphase CFD simulations. Based on the previous experimental facility for visualizing flow patterns in an ESP, the entire flow domain is constructed. The high-quality structured mesh comprising hexahedral grids is generated using multi-block technique in ANSYS ICEM. Mesh independence is confirmed by comparing numerical results with catalog curves. For transient two-phase simulation, the realized RNG k-ε turbulence model with volume of fluid (VOF) and Eulerian multiphase models is successfully implemented in ANSYS Fluent solver. The sliding mesh technique is applied to interfaces where rotating and stationary parts interact. By incorporating the same boundary conditions as experimental study, two different cases with fixed liquid flow rates and varying gas flow rates are selected to conduct CFD simulations. The comparison of numerical results against experimental visualizations shows that the two-fluid Eulerian model is superior to VOF model in simulating gas/liquid flow in a rotating ESP. The single-phase simulation results match catalog curves of ESP, which validates the numerical methodology. For gas-liquid simulations, the simulated flow patterns with Eulerian model agree well with visualization experiments. The distinct flow patterns prevailing inside the rotating ESP impeller are captured by CFD simulations, including dispersed bubble flow, bubbly flow, and intermittent flow.

Gas-liquid downward flow through narrow vertical conduits: effect of angle of entry and tube-diameter on flow patterns

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Amit Kumar ◽  
Gargi Das ◽  
Subhabrata Ray ◽  
Jay Mant Jha ◽  
Amit K. Thakur ◽  
...  
Keyword(s):  
Flow Pattern ◽  
Liquid Flow ◽  
Glass Tube ◽  
Stratified Flow ◽  
Flow Patterns ◽  
Tube Diameter ◽  
Downward Flow ◽  
Flow Rates ◽  
Included Angle ◽  
Flow Through

Abstract The present study investigates the flow pattern characteristics of air-water co-current down-flow in millichannels. The experiments have been performed in glass tube of diameter 0.0042 and 0.008 m. The fluids are injected through Y entry the included angle between the Y arms being 45°, 90°, 135°, and 180° (T Entry). The investigation reveals that the flow patterns are function of tube-diameter, and angle of fluid entry. Interestingly, stratified flow has been observed for steeper Y entry section at low liquid flow rates.

scholarly journals Influence of Hydrodynamic Conditions on the Type and Area of Occurrence of Gas–Liquid Flow Patterns in the Flow through Open–Cell Foams

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3254
Author(s):  
Roman Dyga ◽  
Małgorzata Płaczek
Keyword(s):  
Flow Pattern ◽  
Liquid Flow ◽  
Flow Patterns ◽  
Metal Foams ◽  
Hydrodynamic Characteristics ◽  
Internal Diameter ◽  
Open Cell ◽  
Flow Through ◽  
Open Cell Foams ◽  
Gas Liquid Flow

This paper reports the results of a study concerned with air−water and air−oil two–phase flow pattern analysis in the channels with open–cell metal foams. The research was conducted in a horizontal channel with an internal diameter of 0.02 m and length of 2.61 m. The analysis applied three foams with pore density equal to 20, 30 and 40 PPI (pore per inch) with porosity, typical for industrial applications, changing in the range of 92%–94%. Plug flow, slug flow, stratified flow and annular flow were observed over the ranges of gas and liquid superficial velocities of 0.031–8.840 m/s and 0.006–0.119 m/s, respectively. Churn flow, which has not yet been observed in the flow through the open–cell foams, was also recorded. The type of flow patterns is primarily affected by the hydrodynamic characteristics of the flow, including fluid properties, but not by the geometric parameters of foams. Flow patterns in the channels packed with metal foams occur in different conditions from the ones recorded for empty channels so gas−liquid flow maps developed for empty channels cannot be used to predict analyzed flows. A new gas−liquid flow pattern map for a channel packed with metal foams with the porosity of 0.92–0.94 was developed. The map is valid for liquids with a density equal to or lower than the density of water and a viscosity several times greater than that of water.

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